Raipur: In wake of the deadly Maoist attack on the Congress Parivartan rally in Chhattishgarh, more than 1,000 security personnel have been pumped into the jungles of the Naxalite-infested Bastar region for a major offensive against the ultras. "Over thousand security men are on a combing operation in the region (Bastar) after the attack on Congress leaders," director general of police Ramniwas told on Monday.